Analysis of effects on primary frequency control and power grid stability of different control logic

Many researches have focused on the stability analysis of power systems based on frequency response models. A constant gain value is often used to represent a governing system of a prime mover, which may be proper for a classic hydraulic governor but not suitable for modern digital electro-hydraulic (DEH) control systems. PID controllers, pressure or load feedbacks, frequency deviation feed-forwards and coordinated boiler-turbine controls are used widely for practical generation units to optimize the response characteristics of the units. Few studies have considered the effects of most elements mentioned above on the dynamic analysis of power systems. Most typical governing systems are modeled in this paper. Their effects are studied for power system stability analysis. Some of the elements are verified to be critical for the system dynamics and are proposed for power system modeling on dynamic stabilities. The results may help for power system modeling or grid stability analysis.